Reversing switch assembly



Oct. 27,1970 LAWRENCE ET AL 3,536,868

REVERSING SWITCH ASSEMBLY Filed Jan. 29, .1969 4 Sheets-Sheet 1 l 30' INVENTORS 5L LELAND E.LAWRENCE JOHN L. HAYDU 1. U DONALD V-ZUNFT ATTORNEY Oct. 27, 1 .0 E. LAWRENCE ET"AL 3,536,868

REVERSING SWITCH ASSEMBLY 4 Sheets-Sheet 2 Filed Jan. 29, 1969 INVENTORS LELAND E. LAWRENCE DONALD V. ZUNFT JOHN L.HAYDU ATTORNE Oct. 27., 1970 E. LAWRENCE ETAL I 3,536,868

REVERSING SWITCH ASSEMBLY Filed Jan. 29, 1969 4 Sheets-Sheet 5 S R O T N E V N LELAND E. LAWRENCE DONALD V. ZUNFT JOHN L. HAYDU w Maw ATTORNEY Oct. 27, ,1970 LAWRENCE ET AL REVERSING SWITCH ASSEMBLY 4 Sheets-Sheet 4 Filed Jan. 29, 1969 N REW OR T U N D ELZV.

EOO LDJ ATTORNEY United States Patent 01 fice 3,536,868 Patented Oct. 27, 1970 U.S. Cl. 200-50 Claims ABSTRACT OF THE DISCLOSURE A reversing switch assembly includes side-by-side switches interlocked by a roller that is engageable by the actuator of either switch to be moved to a blocking position with respect to the other. The terminals of the switches are interconnected by bus bar assemblies comprising preformed terminal connectors received in insulating holders.

BACKGROUND OF THE INVENTION This invention relates particularly to three-phase reversing switches of the type comprising two side-*by-side switches, one connected for forward operation and the other for reverse. The invention is, however, equally applicable to other interlocked switch assemblies such as two-speed motor controls.

In a reversing switch of this type, it is necessary to have an interlock between the two switches to prevent either from closing while the other is closed, and it is also necessary to provide for interconnection of the terminals of the two switches to allow the desired mode of operation from a single power source. While various arrangements have been used and proposed for these purposes, many have been unduly complex or expensive, unreliable, or otherwise unsatisfactory.

SUMMARY OF THE INVENTION It is an object of this invention to provide a reversing switch or similar interlocked assembly in which there is a simple but highly effective interlock arrangement including a roller that is moved upon actuation of one switch to block closing of the other.

Another object of the invention is to provide an assembly which includes unique bus bar assemblies to provide for the desired connections between the terminals of the member switches.

It is still another object of the invention to provide a reversing switch assembly including particularly suitable electromagnetic switches that are versatile in that they may be used in either vertical or horizontal orientation.-

The foregoing and other objects and advantages that will become apparent are provided in an assembly that is highly reliable and efficient while still 'being relatively simple and inexpensive.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a top plan view, partially broken away, of a reversing switch assembly formed according to the invention,

FIG. 2 is a front end view in elevation, also partially broken away, of the assembly of FIG. 1,

FIG. 3 is a view in cross section through the plane 3-3 shown in FIG. 2, but with one portion of the switch being shown in exploded relationship with respect to the rest to allow a more clear showing,

FIG. 4 is an enlarged view in cross section through the plane 44 shown in FIG. 3, with dotted lines showing the position of the movable contact carrier of the auxiliary contact assembly when the assembly is in open contact position,

FIG. 5 is an enlarged fragmentary view in cross section through the plane 55 shown in FIG. 2, specifically illustrating the roller interlock of the invention,

FIG. 6 is a view in perspective, partially broken away, which shows the upper bus bar assembly of the reversing switch of FIG. 1,

FIG. 7 is a front view of the bus bar assembly shown in FIG. 6,

FIG. 8 is a view in perspective, also partially broken away, showing the lower bus bar assembly of the revers ing switch of FIGS. 1 and 2,

FIG. 9 is a view in cross section through the plane 99 shown in FIG. 8,

FIG. 10 is a view in perspective of one of the switch actuators of the assembly of FIG. 1, with a magnetic armature shown assembled therewith, and

FIGS. 11 through 14 together constitute an exploded view in perspective of the magnetic operating elements of the switches of FIG. 1, with FIG. 11 illustrating a frame member, FIG. 12 illustrating a coil member, FIG. 13 illustrating a magnetic yoke, and FIG. 14 illustrating the magnetic armature which is also shown in FIG. 10.

DESCRIPTION OF THE PREFERRED EMBODIMENT The reversing switch assembly shown herein is made up of two member switches or contactors which are designated generally by the reference numerals 1 and 1'. The switches or contactors 1, 1' are identical in almost all respects, except as will be specifically noted below, and like reference numerals have been used to indicate their several like parts. Each of the switches 1, 1' includes a generally channel shaped metal frame 2 preferably formed of soft steel, and the two frames 2, and therefore the switches 1, 1 are connected together by means of opposite upper and lower machine screws 3, one of which can be seen in FIG. 1, near their base portions. Spacer collars 4 on the screws 3 establish a desired spacing between the frames 2. Mounting holes 5 (see FIG. 11) in the bases of the frames 2 allow the connected switches 1, 1 to be mounted as a unit in an enclosure or on a panel as may be desired.

Each frame 2 receives a molded coil unit 6 and a magnetic yoke member 7, which are shown most clearly in FIGS. 12 and 13, respectively. The coil unit 6 is formed of a suitable insulating material with a coil winding (not shown) embedded therein. Coil terminals 8 are provided to allow the coil to be connected into a suitable control circuit. The coil unit 6 comprises two serially connected, adjacent coils, the windows of which define openings 9 which extend therethrough forwardly and rearwardly when the switches 1, 1' are disposed in horizontal position as shown. A central portion of the coil unit 6 between the openings 9 is shaped to define a spring seat 10.

The magnetic yoke 7 is of conventional laminated construction, and is U-shaped to define legs 11 which project slightly into the openings 9 from the rear. The yoke 7 may be attached to the coil 6 by means of a retainer clip 7a, and is preferably left somewhat loose so that it is free to align itself with the armature 17. When the coil 6 and yoke 7 are assembled, they are inserted as a unit into the frame 2 which is provided with inwardly turned flanges 12 which bear against ledges 13 on the coil 6 to hold the coil 6 and yoke 7 in place. The coil 6 is biased upwardly against the flanges 12 by means of opposite and parallel leaf springs 14 attached to the inner surface of the base portion of the frame 2 (see FIG. 11). The yoke 7 is biased upwardly against the coil 6 by means of a leaf spring 15 attached to the inner surface of the base portion of the frame 2 intermediate the leaf springs 14. The spring 15 also acts as a cushion when the yoke 7 is engaged by the armature.

A movable magnetic armature 16, shown most clearly in FIGS. and 14, is also of laminated construction and is U-shaped to define legs 17 received in the coil openings 9 from the front. At its forward end, the armature 16 is provided with sidewardly extending wings 18 adapted to be received in an actuator as will be described. The armature 16 is biased forwardly or away from the yoke 7 by means of a compression spring 19 which works between the seat 10 and the central or base portion of the armature 16. Energization of the coil unit 6 of course causes the armature 16 to be drawn rearwardly or toward the yoke 7, resulting in a switch closing action as will be described.

There is a switch actuator 20 seen most clearly in FIG. 10 which includes an integrally molded crossbar 21 and three forwardly extending contact cages 22. The rear surface of the crossbar 21 is provided with facing, angularly disposed slots 23 into which the armature wings 18 can be slid for mounting the armature 16 on the actuator 20. A leaf spring 24 seated on the rear surface of the crossbar 21 bears against the central portion of the armature 16 to keep the two elements in a tight fitting relationship. Each contact cage 22 mounts a movable contact spanner 25 which extends outwardly and presents movable contact surfaces on both sides thereof, and a compression spring 26 urges each spanner 25 toward the rear of its cage 22.

A housing 27, also formed of a suitable insulating material, encloses the major portion of the actuator 20 and is connected to the frame 2 by means of screws 28.

Mounted in the housing 27 are upper and lower stationary contacts 29 which present stationary contact surfaces facing the contact surfaces of the spanners 25 and which extend outwardly above and below the housing 27 where they are arranged in banks and provided with terminal screws 30 for making appropriate line connections as will be described.

An arc hood 31 (see FIGS. 1 and 3), formed of a suitable insulating and heat resistant material, is mounted on the housing 27 by means of screws 32. The hood 31 has rectangular side bosses 33 and upper and lower bosses 34, all of which are received in corresponding notches or recesses in the main housing 27 so that the hood 31 and housing 27 have a dovetailed fitwith the hood 31 extending substantially into the housing 27 so that it fully surrounds and encloses the area around the movable and stationary contact surfaces. The upper and lower bosses 34 are preferably not identical to insure that the hood 31 can be assembled in only one orientation, and as can be seen in FIG. 2 in the preferred embodiment shown herein the upper boss 34 has a triangular tip whereas the lower boss 34 has a rectangular tip for this purpose. It is desirable to minimize the size of the chamber around each set of contacts to provide for enhanced arc extinguishment, and for this purpose the hood 31 is provided with internal webs or walls 35 which extend between adjacent sets of contacts 25, 29.

The forward surface of the hood 31 is provided with openings 36 through which the forward ends of the contact cages 22 extend and move to operate auxiliary contact assemblies designated generally by the reference numeral 37. In the preferred embodiment shown, there are two auxiliary contact assemblies 37 for each of the switches 1, 1', but it will be obvious that one, two or three such assemblies 37 might be used depending on circuit requirements. Each auxiliary contact assembly 37 comprises an insulating housing 38 which is attached to the arc hood 31 by means of screws 39 that also serve as terminal screws. Stationary contacts 40 extend inwardly from both the top and bottom of the housing 38 to present upper and lower stationary contact surfaces. A movable contact carrier 41 is forwardly and rearwardly slidable in grooves formed in the side walls of the housing 38., and carries a movable contact spanner 42, preferably of the longitudinally split type shown in US. Pat. No. 3,272,949 to insure good electrical contact, which presents opposite movable contact surfaces facing the stationary contacts 40. A compression spring 43 seated against the forward surface of the housing 38 urges both the spanner 42 and the carrier 41 rearwardly or toward a closed contact position. The forward surface of the housing 38 is also provided with openings 44 at the side margins thereof to permit one to observe whether the auxiliary contacts are in open or closed contact position as indicated by the position of the carrier 41. FIG. 3, as well as the full lines of FIG. 4, show the auxiliary contact 37 in closed position like it would be if joined to the switch 1 wherein the carrier 41 is urged rearwardly and hidden from view, while the dotted lines of FIG. 4 show the contact 37 in open position wherein the carrier 41 is urged forwardly as will be described to be visible through the openings 44.

In FIG. 1, the switch 1 is shown in a closed condition while the switch 1 is shown as being open. When either switch 1, 1' is in open condition, with the coil 6 not energized, the spring 19 holds the armature 16 and therefore the actuator 20 in a forward position in which the movable contact spanner 25 is removed from the stationary contacts 29 as illustrated in dotted lines in FIG. 3. In this position, the forward end of the cages 22 have moved the auxiliary contact carriers 41 forwardly, the spring 19 being strong enough to override the springs 43, so that the auxiliary contacts are also open. Upon energization of the coil, however, the armature 16 is moved rearwardly which brings the movable contact spanners 25 against the stationary contacts 29 to close the switch, and this same movement frees the carriers 41 so that the auxiliary contacts are also closed. Although normally open switches are shown, it will be obvious that normally closed, early break or normally closed, late break switches may be substituted.

The structure and operation of the switches 1, 1' are obvious without further showing or description. Although the particular, horizontally oriented switches 1, 1 shown and described herein are specially suitable, it will also be obvious that other known types of switches might be used in the reversing switch.

The two switches 1, 1' are interconnected in electrically conventional fashion, although the means for interconnection are novel as will be described, to be adapted for reversing control. That is, the upper terminals 30 of the two switches 1, 1', which are on the input side as contemplated herein, are connected in what can be termed corresponding fashion with the leftmost terminal 30' of the switch 1 being connected to the leftmost terminal 30 of the switch 1, the center terminal to the center and the right terminal to the right. The lower terminals 30, which lead to a motor (not shown) are connected in reverse fashion, with the leftmost terminal 30 of the left switch 1 being connected to the right terminal 30' of the switch 1', the two center terminals 30 to one another and the right terminal 30 of the switch 1 to the left terminal 30 of the switch 1'. With suitable known connections to a three phase motor, this means that actuation of the switch 1 will cause the motor to run in one direction whereas actuation of the switch 1' will cause it to run in the other direction. It is obviously important for this type of connection that interlock means be provided to insure against simultaneous actuation of the two switches 1, 1'.

The actuators 20 of the two switches 1, 1 move reciprocally along parallel paths of movement in a common plane, and their paths can be said to correspond in that forward movement of either results in opening of the switch whereas rearward movement results in a closing action. Interlocking to prevent simultaneous operation is accomplished by having overhanging portions of the crossbars 21 engage a cylindrical interlock roller 45 which is disposed between the actuators 20 with its longitudinal axis normal to the plane of their movement.

The roller 45 comprises a longitudinal shaft 46 and opposite outer segments 47 and a central segment 48, all independently rotatably mounted thereon. C-type snap-in washers 67 are received in circumferential grooves provided on the shaft 46 at opposite ends of the roller 45 for the purpose of retaining the roller segments 47, 48 in place. The diameters of the outer segments 47 are the same and are substantially greater than the diameter of the central segment 48, and the axial extent of the central segment 48 is approximately equal to the total axial extent of the two outer segments 47.

The shaft 46 extends outwardly at both ends of the roller 45, and rollably rests on a clip 49 which serves as a support for the roller 45.

As can be seen in FIGS. 1 and 3, the facing side walls of the housing 27 are provided with openings 50 through which both the clip 49 and roller 45 extend or move. The clip 49 is of an inverted U-shape to define rearwardly extending legs 51 which are inside the side limits of the housings 27 and extend rearwardly to bear against opposite inner surfaces of the frames 2. The central portion of the clip 49 is open at its center to receive the body of the roller 45 and defines opposite, parallel rails 52 which rollably receive the ends of the shaft 46. The lower rail 52 also provides support for the body of the roller 45 as shown in FIG. 2, while the spacing of the elements of switches 1, 1 surrounding the roller is such that the roller 45 is precluded from falling significantly out of its proper orientation.

The crossbars 21 extend partially over the roller 45 to define facing, overhanging portions 53 which are engageable with the roller 45. As seen most clearly in FIGS. 2 and 5, the overhanging portion 53 of the right-hand switch 1 comprises a tapered surface which is continuous across hte entire width. The overhanging portion 53 of the left-hand switch 1 is generally similar, but the upper and lower edges are cut away so that only the central portion 54 extends laterally for the full extent, this portion 54 facing and corresponding in size to the central roller segment 48.

When both switches 1, 1 are open, the roller 45 is generally centrally located between the actuators 20 and is spaced rearwardly of both of them. If switch 1 closes as seen in FIGS. 1 and 2, however, the crossbar 21 moves rearwardly with the armature 16 so that the central overhanging portion 54 engages the central roller segment 48 and shifts the roller to the right as seen in FIGS. 2 and to a blocking position where, for so long as the switch 1 remains closed, the switch 1' will not be able to close because the roller 45 will block rearward movement of the crossbar 21 and, therefore, the actuator 20. Assuming again that both switches 1, 1' are open, closing of the switch 1 will correspondingly cause the roller 45 to be moved to the left where it will block closing of the switch 1. In this case, however, the overhanging portion 53 of switch 1' will engage the outer roller segments 47. Again, for so long as the switch 1 remains closed it will be impossible to close the switch 1 because of the blocking position of the roller 45.

The specific construction shown for the roller 45 is particularly advantageous for it reduces frictional wear and any tendency to bind when the overhanging portions 53 of both crossbars 21 engage the roller 45. This is accomplished by the fact that the overhanging portion 53 of switch 1' will engage only the outer roller segments 47 causing them to rotate in one direction as they are displaced, while the central overhanging portion 54 of switch 1 will engage only the central roller segment 48 causing it to rotate in the opposite direction as it is displaced. If only a single roller unit of constant diameter were used, engagement of both crossbars 21 would produce a wedging action that would tend to prevent the switches from opening when deenergized. Once wedged together, any tendency to release is opposed by friction between the roller surface and the crossbar surfaces. Use of the threesegment roller 45 eliminates all sliding between the roller segments and crossbars and thus eliminates the wedging and binding associated with single roller action.

Another of the advantages provided by the present invention is ability to remove the magnet assembly, i.e., the coil 6, yoke 7 and armature 16, from each frame 2 without disturbing the housing 27, actuator 20, arc hood 31 and auxiliary contact assemblies 37. As shown mounted in FIG 1, the coil 6, yoke 7 and armature 16 can be translated upwardly as a unit for removal from the channel shaped frame 2, the upper rear surface of each housing 27 being cut away so that the housing 27 is clear of the path of travel of said unit. In removing and reinserting parts of the aforesaid magnet assembly of each switch, the housing 27, actuator 20, etc. are left undisturbed, this being facilitated by the ability to slide the armature wings 18 into and out of the actuator slots 23 to mount or-dismount the armature 16 on the actuator 20 with the armature 16 sliding clear of the actuator 20 and of any blocking interference with the housing 27.

Turning now to FIGS. 2, 6 and 7, the upper terminals 30 of switches 1, 1, which are on the input side of the reversing switch, are interconnected by a unique bus bar assembly 55 which is particularly useful not only for the reversing switch construction shown but also in other applications. The upper bus bar assembly 55 comprises an elongated insulating holder 56 which is provided with a plurality of lengthwise, inwardly and outwardly spaced slots 57, and a plurality of preformed, rigid, U-shaped, terminal connectors 58. The connectors 58 have central parts 59 which are received in the slots 57, as well as arms 60 extending inwardly therefrom whose free ends are connected to the terminals 30. In order to prevent loss of the holder 56, and thus loss of insulation between the connectors 58, after the bus bar assembly 55 is connected to the terminals 30, the slots 57 are arranged so that the inner arms 60 of the two uppermost connectors 58 engage the front surface of the holder 56 as best seen in FIG. 7, while the central parts 59 of the connectors 58 engage the holder 56 from the rear. This unique front and rear engagement of the holder 56 by the connectors 58 prevents the holder from falling off the connected assembly 55.

The lower terminals 30 of switches 1, 1', which are on the motor side of the reversing switch, are interconnected in reverse fashion to the upper terminals by a second form of bus bar assembly 61 as shown in FIGS. 2, 8 and 9. The lower bus bar assembly 61 comprises an elongated insulating holder 62 which in this case is provided with a plurality of inwardly and outwardly spaced, lengthwise slots 63 including one 63a which is inverted. Additionally, preformed, rigid, U-shaped, terminal connectors 64 are provided for the assembly 61, the central parts 65 of which are received in each of the slots 63 from the rear and in slot 63a from the front, and the arms 66 of which extend inwardly from the central parts 65 to be connected to the lower terminals 30. This arrangement also provides front and rear engagement which will prevent loss of the insulating holder 62 when the bus bar assembly 61 is connected to the terminals 30.

Thus, rigid and preformed bus bar assemblies 55, 61 are provided which are compact and which greatly simplify the task of interconnecting the terminals 30 of switches 1, 1', while at the same time having insulating holders 56, 62 respectively which are easy to manufacture and which are uniquely designed so as not to be removable when the assemblies 55, 61 are interconnecting the terminals 30.

Although specific structural forms of this invention have been illustrated and described, the invention is not limited to the specific constructions herein disclosed and it is expected that those skilled in the art may be able to devise changes in or alternatives to the disclosed structural features while still practicing this invention.

We claim:

1. In a reversing switch assembly or the like including a pair of switches disposed in side-by-side relationship and having actuators reciprocally movable along fixed corresponding parallel paths in a common plane, said actuators being shaped to provide overhanging portions and positioned so that said overhanging portions face each other, the combination therewith of a cylindrical interlock roller disposed between the paths of travel of the actuators with its longitudinal axis normal to the actuators common plane of movement, the roller being engageable by the overhanging portions of both actuators during operation thereof, and means are provided so that engagement by either actuator with said roller linearly displaces the roller in the plane of movement of the actuators to a position to block movement of the other actuator to its operated position.

2. The combination of claim 1 wherein the roller comprises a longitudinal shaft, and opposite outer roller segments of the same diameter and a central roller segment of smaller diameter, all independently rotatably mounted on the shaft, the axial extent of the central roller segment being approximately equal to the total axial extent of the outer roller segments, and the overhanging portion of one actuator engages only the outer roller segments while the overhanging portion of the other actuator engages only the central roller segment.

3. The combination of claim 2 wherein the shaft extends outwardly of the outer roller segments, and the switches are in housings including side walls with facing openings through which the roller extends, and there is a U-shaped clip which extends between the switches through the openings having legs that engage opposite inner surfaces of the side walls and a central portion with an open center to receive the roller segments and defining opposite, parallel rails which are parallel to the actuators common plane of movement and which rollably mount the ends of the shaft.

4. The combination of claim 1 wherein each switch has a plurality of terminals arranged in a bank, the

banks of the switches being in side-by-side relationship,

and a bus bar assembly interconnects the terminals of the switches, said assembly comprising an elongated insulating holder provided with a plurality of lengthwise, inwardly and outwardly spaced slots, and a plurality of preformed, rigid terminal connectors each of which includes a pair of arms connected to and leading outwardly from respective terminals in each switch bank, and a central part connecting said arms outwardly of the terminals which is received in a slot to be held apart and insulated from other terminal connectors of the assembly.

5. The combination of claim 4 wherein the slots of the insulating holder are arranged so that an arm of at least one terminal connector engages one surface of the holder, while the central parts of the terminal connectors are received in slots on an opposite surface thereof.

6. The combination of claim 4 wherein at least one slot of the insulating holder isinverted with respect to the remaining slots, the holder being adapted for engagement from opposite sides thereof by the terminal connectors.

7. The combination of claim 1 wherein the roller comprises a longitudinal shaft, and opposite outer roller segments of the same diameter and a central roller segment of smaller diameter, all independently rotatably mounted on the shaft, the shaft extending outwardly of both outer roller segments,

the overhanging portion of 'one actuator is adapted to engage only the outer roller segments while the overhanging portion of the other actuator is adapted to engage only the central roller segment,

the switches are in housings including side walls with facing openings through which the roller extends, and there is a U-shaped clip which extends between the switches through the openings having legs that engage opposite inner surfaces of the side walls and a central portion with an open center to receive the roller segments and defining opposite, parallel rails which are parallel to the actuators common plane of movement and which rollably mount the ends of the shaft, and

each switch has a plurality of terminals arranged in a bank, the banks of the switches being in side-byside relationship, and a bus bar assembly interconnects the terminals of the switches, said assembly comprising an elongated insulating holder provided with a plurality of lengthwise, inwardly and outwardly spaced slots, and a plurality of preformed, rigid terminal connectors each of which includes a pair of arms connected to and leading outwardly from respective terminals in each switch bank, and a central part connecting said arms outwardly of the terminals which is received in a slot to be held apart and insulated from other terminal connectors of the assembly, the slots being arranged so that a part of at least one connector engages the holder on one side thereof and a part of at least another connector engages the holder on an opposite side thereof to prevent the holder from being removed when bus bar assembly terminal interconnections are made.

8. In a reversing switch assembly or the like including a pair of switches disposed in a side-by-side relationship, with each switch having a plurality of terminals connected in a bank, the banks of the two switches being in side-by-side relationship, the improvement wherein: there is a bus bar assembly interconnecting the ter- Ininals of the two switches, said assembly comprising an elongated insulating holder provided with a plurality of lengthwise, inwardly and outwardly spaced slots, and a plurality of preformed, rigid terminal connectors each of which includes a pair of arms connected to and leading outwardly from respective terminals in each switch bank, and each of which includes a central part connecting said arms outwardly of the terminals which is received in a respective one of said slots to be held apart and insulated from other terminal connectors of the assembly.

9. The combination of claim 8 wherein the slots of the insulating holder are arranged so that an arm of at least one terminal connector engages one surface of the holder, While the central parts of the terminal connectors are received in slots on an opposite surface thereof.

10. The combination of claim 8 wherein at least one slot of the insulating holder is inverted with respect to the remaining slots, the holder being adapted for engagement from opposite sides thereof by the terminal connectors.

References Cited UNITED STATES PATENTS 3,240,889 3/1966 Lawrence et al. 3,219,887 11/1965 Gerg et a1. 317-119 XR ROBERT K. SCHAEFER, Primary Examiner M. GINSBURG, Assistant Examiner US. Cl. X.R. 174-72; 335- 

